Ball or pebble mill.



G. F. W. HOPE & H. W. J. CHEFPINS. BALL 0R PBBBLE MILL.

lAPPLICATION FILED JUNE 29, 1912. 1,054,41 5, Patented Feb. 25, 1913.

4 SHEBTS-SHEBT l.

@we @975W /W @M/@fw G. F. W. HOPE & H. VW. J. CHEFFINS.

BALL 0R PBBBLB MILL. APPLICATION FILED Juul.` 29

Patented Feb. 25, 1913.

4 EERSTE-SHEET 2.

if] W G. F. W. HOPE & H. W. J. CHBFFINS. BALL 0R PBBBLB MILL.

APPLIoATIoN FILED JUNI; 29, 1912.

1,054,41 5, Patented Feb. 25, 1913.

4 SHEETS-SHEET 3.

G. F. W. HOPE & H. W. J. CHEFPINS. BALL 0R PEBBLB MILL.

APPLIoMeoN FILED JUNI: ze, 1912.

1,054,415A Patented Feb. 25, 1913.

4SHEETS-BHEET4.

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15u/enfans @MM UNITED STATES PATENT OFFICE.

GEORGEFOUNTAINE WEARE HOPE, OF STANFORD LE HOPE, AND HAROLD WILLIAMJOSHUA CHEFFINS, OF SEAFORD, ENGLAND.

BALL OR PEBBLE MILL.

Y To all whom it may concern Be it known that we,l GEORGE FOUNTAINEVEARE Horn, a subject of thel King ot' Great Britain, residing at theBungalow, Stanford le Hope, in the county of Essex, England, and HAROLDWILLIAM JOSHUA CHEF- rINs, a subject of the King of Great Britain,residing at 5 Marine Parade, Seaford, in the county of Sussex, England,have invented new and useful Improvements in Ball or Pebble Mills, ofwhich the following is a specification.

. a separate settling chamber by compressed air or by means of a fan.

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According to our invention we arrange in the mill .or the like, which isconveniently` in the form of a rotating cylinder mounted on rollers asabove described, a stationary chamber or a series of chambers which maybe arranged in an upright position on the central axis of saidmill or iffound desirable. at any convenient angle above the center of said mill.The said stationary chamber is provided with an inlet at its upper endand an outlet leading to the hollow trunnicn or stationary disk or disksat the end or ends of 'the cylinder. The inlet of said chamber isprovided with a suitably vshaped hood adapted to prevent the entranceinto the chamber of any large particles which may be carried to the topof the mill during its rotation.

We find in practice that it is desirable to provide a convenient methodof grading the consistency of the powder extracted from the mill and inorder to do this we prefer to arrangethe extracting chamber in such amanner that the height ofV its inlet from the center of the mill can beadjusted. It will be obvious that` when the inlet to the chamber isarranged in the highest part Vof the mill only the ktinest dust willpass in through l Specification of Letters Patent.

Application led June 29, 1912.

form of a series of funnels.

Serial No. 706,662.

the inlet to the collecting chamber while when the inlet of said chamberis arranged in a position nearer the level of the material in the millthe eoarser dust will pass with the finest dust into said collectingchamber and from said chamber through the outlet under the influence ofcompressed air or the suction created by the fan or by any other means.l

We provide in the hollow trunnions or disk or disks at the end or endsof the mill a pipe forming a compressed air inlet provided with a seriesof jets adapted to direct compressed air upon the balls or pebblesduring the rotation of themill in this manner preventing the powder fromcollecting on the surface of the pebbles and thus causing cushionedsurfaces thereon which destroy their grinding efficiency. Y

Our invention is illustrated by way of example in the accompanyingdrawings in which- Figure l. shows a side View partly in section of themill. Fig. 2. shows a seetion on the line A-B of Fig. 1. Fig. 3. showsan alternative form of our invention in which the extracting chamber isin the Fig. 4l. shows a detail sectional view of an alternative form ofa portion of the device. Fig. 5. shows an end elevation of Fig'. 4.

' As` shown in Figs. l and 2 of the, drawings, wend it desirable tosupport the periphery of the mill l on a series of rollers 2 instead ofon a central axis. With such an arrangement the central hollow trunnionscan be dispensed with altogether and we may form the ends or part of theends of the mill of stationary disks 3 of suitable material, said diskssupportin the chute 17 and the air inlet tube 4 anc outlet conduit 5 forthe powdered material ground in the mill above the center of the milland consequently allowing of the mill being' loaded above its center ofgravity and thus increasing its output. As shown in Figs. l and 2 we mayarrange the extract: ing chamber in the form of a narrow box 6 arrangedeither at an angle as shown or in an upright or approximately uprlghtposition in the mill and extending throughout its length. The top ofsaid chamber is open to receive the powder extracted in the mill and theoutlet from said chamber leads to the outlet conduit 5 through thehollow trunnion. At a suitable height above the Patented Feb. 25, 1913.`

lltl

Y pressed air upon the balls or pebbles 12 aty chamber 6 we larrange ahood 7 adapted to prevent the entrance of any large particlesl which maybe carried to the upper part of the mill during its rotation. Wei-preferto provide the box chamber with telescopic sections, such as 8, so thatwhen desired the position of the top of said chamber with regard to thecentral axis of the mill can be adjusted in order that the consistencyof the powder extracted can be graded conveniently. In order to allow ofa convenient adjustment of the telescopic sections 8 of the chamber 6and to insert the pebbles or balls we may arrangea manhole 9 in aconvenient position on the periphery of said mill through which the saidtelescopic sections can be conveniently adjusted. The set screws 10 areprovided by which the sections 8 of the chamber 6 can be locked in thedesired position. The mill may, if desired be made in two parts (notshown) so that it can be easily taken to pieces and each end may be maderemovable. If compressed air is used by discharging the powder from themill through the outlet conduit 5 we provide in the inlet pipe 4 aseries of openings 11 adapted to direct a series o-f jets of comrightangles to the general level of the material during the rotation of themill, as shown by the arrows in Fig. 2, in this manner preventing theowder from collecting on the surface of said) pebbles and thus causingcushioned surfaces thereon which destroy their grinding efficiency. Inthe mills of this class in which compressed air has been used the airhas been directed from a single jet at one end of the mill to sweepacross the pebbles and to pass out at the other end of the mill. Thematerial to be ground is fed into the mill through the chute 17 providedwith a series of outlet passages 18 through which there is a constantfeed to the mill during its rotation while any material remains in thechamber 17. The powder suspende-d in the-mill during its rotation passesunder the :hood 7 into the chamber 6 and from thence to the outletconduit 5, as shown, by the arrows in Figs. 1 and 2. Means may also beprovided such as sliding valves, whereby the size oA the inlet passages18 can be adjusted-s0 as to vary the volume of material fed tol themill, according to the speed at which the mill is rotated and the natureof the material to be ground.

In the alternative form of our invention illustrated in Fig. 3, wearrange in the mill a central pipe 13 leading to the outlet conduit 5and mount on said passage a series of funnels 14 with curved telescopingends, conveniently turned alternately in opposite directions, as shown,the pipe 13 and branches 14 constituting the extraction chamber. Thepowder suspended in the air during. the rotation of the mill passesthrough the openings 15, 15a glas shown by the arrows) of said curved ens, while any large particles which may be carried to the top of the millare prevented from Aentering by the arched top walls 16 which constitutethe hood over the inlet openings.

In Figs. 4 and 5 we show another form of a detail portion of ourinvention in which we provide means whereby the inlet conduits to themill and the outletconduit frrm the extracting chamber are supported bya stationary disk of convenient diameter arrangedin one endl of themill, the other end of the mill being attached to and adapted to rotatewith the periphery of the mill. The edge 20 of the circular openingformed in the rotating end of the mill which receives the stationarydisk 21', is provided with an outwardly extending flange 22 on theinternal surface of which is arranged a worm 23. The said disk 21 isprovided with a corresponding outwardly extending flange 24. The saidworm 23 isadapted to feed back into the mill any dust which may passfrom said mill in to the joint formed by said surface 20 and theperiphery of theV disk 21. We arrange a hollow ring 25 adapted to coverthe outer end of the joint between said stationary disk 21 and therotating end of the mill. Compressed air is led into said hollow ring 25through a passage 26 and this compressed air acts in.-

addition to ,said worm 23 and returns to ,the mi'll any dust which mayaccumulate in the joint. The air pressure in the ring is higher than thepressure in the mill. In some cases we may nd it desirable to dispensewith the worm 23 and rely upon compressed air alone to return the dustt0 the mill. The ring 25 is retained in position by a series of springs27 arranged between the` cuter face of said ring and the inner faces ofthe arms 28 of a standard 29. It will be obvious instead of the arms 28the upper part of the standard 29 may be in the form of a disk. AThestationary disk 21 is conveniently attached to said standard 29 by meansof the connecting rod 30. In this arrangement the extracting chamber 6is supported `by said stationary disk 21 conveniently by its outletconduit 32 which passes through said disk and forms a return pipeparallel with or approximately parallel with the inlet conduit 33 forthe chute and' the inlet tube 34 leading compressed air into the mill toblow upon the pebbles or balls as previously described. In thisarrangement of the mill we may open the chute or inlet conduit 33 forthe material to be fed into the mill, to the source of compressed airthus enabling the use of compressed air for feeding the material fromthe chute into the mill. The arrangement of the inlet for compressed airin the chute is a usual and convenient one in mills of this class inwhich compressed air is used for separating the dust ground in the mill.

It is obvious that the extracting chamber shown in Figs. 1 and 2, orthat` shown in Fig. 3, maybe substituted for lthe arrangementillustrated in Fig. 4. It is also to be understood that the extractingchamber shown in Fig. 4 may be provided with a hood and telescopic Wallsin the same manner as illustrated in Fig. 2.

Although we have described as means for withdrawing the powder ground inthe mill the use of compressed air or suction it must be understood thatif desired we can arrange a mechanical feed beneath the chamber 6.

W'hat we claim is-- l. In a ball or pebble mill the combination of amill chamber, an inlet conduit for the material to be ground, aninternal extracting chamber having an upper inlet rpening, a hoodcovering said inlet opening to said extracting chamber, and adapted toprevent the entrance of any large particles which may be carried to thetop of said extracting. chamber, said hood and the walls of saidextracting chamber being relatively adjust-able, and an outlet yconduitleading from said extracting chamber for thel powder extracted. f

2. In a ball or pebble mill the combination of a mill chamber, an inletconduit for the material to be ground, an internal extracting chamberhaving an inlet opening affording communication between said extractingchamber and the mill chamber, means for adjusting the walls of saidchamber'to vary the position of said inlet opening in relation to thelevel of the material in said mill chamber, a hood covering said inletopening to said extracting chamber adapted to prevent the entrance ofany large particles which may be carried to the top of said extractingchamber, and an outlet conduit leading from said extracting chamber forthe'powder extracted.

3. In a ball or pebble ymill the combination of a mill chamber, an inletconduit for the material to be ground, an internal extracting chamberhaving telescoping walls provided with an inlet opening affordingcommunication with said extracting chamber and the mill chamber, a hoodcovering said inlet opening to said extracting chalnber adapted toprevent the entrance of any large partia cles which may be carried tothetop of said 'said extracting .chamber for the pow rom said extractingchamber for inlet conduit having a series of openings in chamber, and anoutlet'conduit leading from 4 said extracting chamber for the powderextracted.

5. In a ball or pebble mill the combination of a mill chamber, an inletconduit for the material to be ground, a compressed air inlet pipeextending in parallel relation with said material inlet conduit having aseries of openings in said pipe arranged at intervals across the millchamber and adapted to direct compressed air upon the balls or pebblesat right angles to the general level of the material during the rotationof the mill, an internal extracting chamber having an inlet openingaii'ording communication between said eX- tracting chamber and the millchamber, a

hood covering said inlet opening to said extracting chamber and adaptedto prevent the entrance of any large particles which may be carried tothe top of said extracting chamber, and anoutlet conduit leadin from erextracted.

6. In a ball or pebble mill the combination of a cylindrical millchambermounted 011 a series of rollers, a stationary end to said mill chamber,an inlet conduit for the material to be ground mounted in saidstationary end above the axis of rotation of the mill, an internalextracting chamber having an inlet opening affording communicationbetween said extracting chamber and the mill chamber, and an outletconduit leading from said extracting chamber for the powder extracted.

7. In a ball or pebble mill the combinatlon of a cylindrical millchamber mounted en a series of rollers, a stationaryV end to said millchamber, an inlet conduit for the material to be ground mounted in saidstationary end above the axis of rotationof the-mill chamber, aninternal extracting'chamber having an inlet opening affordingcommunication between said extracting chamber and the mill chamber,means for adjustin the Walls of said chamber to.vary the position ofsaid inlet opening in relation to the level of the .7.

material in said mill chamber, and an outlet conduit leading from saidextracting chamber for the powder to be extracted.

8. In a ball or pebble mill the combination of a cylindricalmill chambermounted on a series of rollers, a stationary end to said mill chamber,an inlet conduit for the material to be ground mounted in saidstationary end above the axis of rotation of the mill chamber, aninternal extracting chamber having telescoping walls and provided withan inlet opening affording communication between said extracting chamberand the mill chamber, a -hood covering said inlet opening to saidextracting chamber and adapted to prevent the entrance of any largeparticles which may be carried to the to-p of said extracting chamber,and an outlet conduit leading from said extracting chamber for thepowder extracted' mounted in said stathe material to be ground vmountedin said.'

stationary disk, an internal extracting chamber having an inlet openingaording communication between said extracting chamber and the millchamber,` and an outlet conduit leading from saidv extracting chamberfor the powder extracted. i Y 10. In a ball or pebble, mill thecombination of a cylindrical mill chamber mounted on a series of rollersand having a flange surrounding a circular opening in the end wall ofthemill chamber, 'a worm on the inner periphery of said flange surrounding.said circular opening, a stationary 'disk' mounted in said circularopening, an inlet jconduit for the material to lbe ground vmountedin'said stationary disk, an internal extracting chamber having an inletopening affording communication between said extracting chamber andthemill chamber,

i means for adjusting the walls of said chamsaid extractingchamber, andan outlet vcon-v duit ,leading from said extracting chamber opening tosaid extracting chamber adapted "to prevent the entrance of any largepar-v ticles which maybe carried to the top of for the powderextractedmounted in said stationary disk.

11.y In a kan .or pebbie min are Combina-f tion of) a cylindrical' millchamber mounted on a4 series of rollers and having a circular opening inthe'end wall of the mill chamber, a` stationary disk mounted in saidcircular opening, means for creating a greater fluid pressure lthanthe'luid pressure in the `mill chamber on the exterior surface of the.joint between said stationary disk Aand the rotating edge of -the endwall'of the mill rsurrounding said circularopening, an inlet conduit forthe material to be ground ,mounted in said stationary disk, an internal.

extracting chamber .having an inlet openingaHording communicationvbetween said extracting chamber and the mill chamber, and an outletconduit leading from said extract- 4 ing chamber for thepowderextracted.

12.'Iii a ball or pebble mill the combina` tion ofa cylindrical millchamber' mounted on a series of rollers and'p'rovided with a circularopening in the end wall of the mill, a stationary disk mountedin saidcircular opening, a hollow ring. adapted to cover the outer end ofthejoint between the stationary disk and the rotating end of the mill,

means for leading compressed air to said hollow ring, van inletconduitfor the ma` terial to b e ground mounted in saidstationary disk, aninternal extracting chamber.v

having an inlet opening affording communication between said extractingchamber and the mill chamber, means` for adjusting the walls of saidextracting chamber to vary the position of -said inlet opening inrelation .to

the level of the material in said mill chainber, and an outlet conduitleadingfrom said extracting chamber for the powder to be extracted.

-l3f In a ball or pebble mill the combinan.

tion of a cylindrical mill chamber mounted on a series of rollers andprovided with a circular opening int-he end wall of the mill, astationary disk mounted in said circular opening, a hollow ring adaptedto cover the outer end of the joint between the stationary extractingchamber having 'telescoping walls and provided'vvith an inletopeningaffording communication between said extracting disk and -the rotatingend of the mill, means chamber and the mill chamber, a hood coveringsaid inlet opening to said extracting chamber and adapted to preventthe' entrance of any large ,particles which may be carried to the topo'f said extracting cham'- ber, and an outlet conduit leading from saidlextracting chamber for the powder to be extracted mounted in saidstationary disk. In testimony whereof we have signed our namestovthisrspeciication in the presence of two subscribing witnesses, d

' GEoRGEroU-Nrlnui Wm'iiii Horiz.

HAROLD -ll/'ILLIAlll JOSHUA CHEFFINS.

, Witnesses: i

LnoNAni E. HAYNES, CLARENCE' P. LIDDEN.

